The invention relates to new techniques and machines for carding textile fibers and particularly to the production of a high quality carded cotton fiber at increased production rate. Additionally, there is an increased ability to remove trash and seed coat particles while preserving fiber staple length. The present invention is designed for the "cotton system" and may be used with synthetic fibers as well as cotton.
Carding of fibers is the disentanglement, cleaning and intermixing of fibers to produce a continuous web or sliver suitable for subsequent processing. This is achieved by passing the fibers between moving surfaces covered with card clothing. Silver is produced on a cotton card with revolving flats or stationary plates. Carding follows opening, blending, and in the case of cotton, a certain amount of cleaning of the bale material. Small tufts are fed to the card in the form of a lap or chute-fed fleece and, after a draft of 50-150, fibers leave the card in the form of a sliver, which may be direct-spun or subjected to further processing prior to the yarn formation operation.
Carding cylinders are typically clothed with metallic wire card clothing consisting of a steel strip with hardened teeth punched along the upper edge and wrapped about a cylindrical roll. The teeth are usually inclined at a prescribed angle. If the teeth of opposing relatively moving surfaces are opposed, the fibers are usually subjected to a carding action or a doffing action depending on the speeds. If the teeth are inclined in the same direction as they approach, then there usually is a stripping or transfer action.
Previously, "tandem" carding machines have been used to produce carded cotton fiber with a high degree of cleanliness and carding. Carding machines of the tandem type are shown in U.S. Pat. Nos. 2,097,046; 3,249,967; 3,097,399; and 4,128,917. These tandem carding machines typically include two carding cylinders arranged horizontally next to each other to provide doubled or increased carding. Carding takes place over the top portions of the cylinders with transfer from one cylinder to the other being carried out by various arrangements of transfer rolls. Due to the tandem arrangements and the fiber path over the top portions, effective carding action is limited to a good deal less than 50 percent of the cylinder circumference or surface area. Typically, the range of effective carding in prior tandem arrangements has been approximately from 20 to about 40 percent of each cylinder in tandem. In one tandem arrangement, a pair of horizontal tandem cylinders has been provided where fiber feeding, transfer, and doffing are done at bottom portions of the cylinder to increase the top portion over which carding may be done. Stationary carding plates are used over the top carding area of each cylinder. Fibers may be carded over about 70 percent of the circumference of the tandem cylinders. This machine is manufactured by Hollingsworth, Inc., of Greenville, S.C., under the name Mastercard. Further, the arrangements of tandem carding cylinders in the prior art have required a large floor space and the tandem train arrangement makes the parts of the machine difficult to access and work on. Carding action has also been limited in the prior art by the revolving carding flat arrangements used, typically used in high quality tandem arrangements, where carding is limited to about 1/4 inch at the heel of the flat, or over only about 1/3 of the carding flat.
A cotton cleaning machine and system is disclosed in U.S. Pat. No. 4,198,731, directed primarily to an improved suction plenum removable for machine inspection. This is a cleaning machine designed to clean exceedingly dirty cotton fibers. Carding and cleaning are done as fibrous stock travels over a top portion of a first cylinder and under the bottom portion of a second cylinder where a transferred fiber mass may be exposed for carding on both sides, even though not clearly apparent. This machine is designed primarily for opening, cleaning, and feeding loose fibers. A carded sliver or web is not produced as in the case of a conventional carding machine. Trash and short fibers that are not desirable for carding are extracted. The cleaned fibers are blown into a hopper for subsequent feeding to a chute feed of a conventional carding machine. The cleaning machine removes up to 25 percent of its input where a typical carding machine is designed to remove about 5 percent of its input.
U.S. Pat. No. 3,081,499 discloses a fiber integrating apparatus for producing a carded web or sliver of cotton or synthetic fibers. A vertical arrangement of carding cylinders is designed to take advantage of a vertical feed arrangement which relies primarily upon gravity and to provide for a carding in reduced space. The apparatus utilizes a triple feed roll arrangement in which two rows feed and one roll clears. The carding takes place mainly between the feed roll and first cylinder and in the transfer area between the first and second cylinders over a nose portion. Some additional carding takes place between a roughened surface of the covers and the cylinders. The surface area of each cylinder over which carding takes place is significantly limited relative to the total area of the cylinders and the carding action is limited. Smaller diameter rolls rotating at higher speeds than conventional carding cylinders are used to reduce loading through increased centrifugal force. However, capacity may be limited by the feed arrangement and limited carding action. While the vertical cylinder arrangement conserves space, the overall configuration, including fiber infeed and take-off does not lend itself to practical or efficient carding.
Conventional carding machines are typically fed by a feed roll/feed plate arrangement which delivers a fiber batt to a licker-in roll which feeds fibers directly to a main carding cylinder. Numerous variations of this arrangement have been proposed. For example, U.S. Pat. No. 4,524,492 discloses a triple licker-in roll arrangement. Two additional licker-in rolls are used to provide some carding and cleaning prior to the main cylinder. A primary carding action takes place between the feed plate and the main carding cylinder. Some carding may also take place during the transfer action between the licker-in rolls. Cleaning is provided by the mote knives below the third licker-in roll. Centrifugal force slings out the heavy motes or trash particles which may be removed by suction.
In prior carding machines, the web is typically taken off by a doffer roll which forms the fibers into a web. Following the doffer roll, a typical take-off may include a stripper roll which strips the fibers from the doffer and a pair of smooth delivery rolls which deliver the web to a trumpet or other condensor which condenses the web into a sliver. The sliver is then coiled into coiler cans by a conventional coiling device. Numerous and various take-off arrangements have been proposed for conventional carding machines. The problems encountered in taking off fiber from a card operating at increased production has been recognized. For example, U.S. Pat. No. 3,946,464 discloses a take-off belt arrangement. A pair of belts revolving parallel to the surface of the delivery rolls condense the web into a sliver which is delivered through a nip of the belts rotating about pulleys. The sliver is drawn off through a trumpet into a coiler head. The transverse belts are maintained in pressing support contact against the surface of the delivery rolls along substantially their entire length to avoid build up of fibers on the delivery rolls. However, it has been found at high production speed that this contacting arrangement may cause the problem it seeks to avoid and that fibers may actually wrap up around the delivery rolls. U.S. Pat. No. 3,825,975 discloses a similar take-off wherein a pair of revolving belts condense a web into a sliver for feeding to a coiler.
The principle of using a motive fluid to convey yarns and webs in textile applications is already known and is discussed in U.S. Pat. Nos. 3,970,231 and 3,976,237.
While various arrangements have been proposed for taking off fiber from a card, there has not been a satisfactory arrangement for starting a card and automatically threading sliver into a coiler can without manual assistance. Typically, when a card is started, the web is manually gathered and threaded through a trumpet where it is condensed as a sliver. Manual threading continues until the sliver is threaded into the coiler can. This is commonly referred to as bringing the end up on a carding machine to start the carding process. U.S. Pat. No. 3,196,492 proposes apparatus for piecing up a severed card web or sliver in an automatic manner. The web is pieced to a severed end of sliver. However, this piecing apparatus does not seek to provide complete threading-up of a sliver upon card start-up. This apparatus would not be effective for use in automatically threading-up sliver into a coiler can. At start-up, there is also the problem that the first, start-up part of the sliver is uneven and contains large lumps and other unwanted fibrous parts.
Accordingly, an object of the present invention is to provide a carding machine having increased production capacity without sacrificing the quality of the carded fibers.
Another object of the invention is the provision of a compact carding apparatus and method including a pair of clothed carding cylinders which provide a carding action substantially increased over that of the prior art and which cards both sides of a fiber mass being transferred between the cylinders contributing to thorough cleaning and parallelization of fibers.
Another object of the invention is to produce high quality carded sliver at high production rates with increased trash and mote particle removal while preserving fiber staple length and quality.
Another object of the present invention is to provide a compact arrangement for a carding machine having increased carding action and capacity.
Another object of the invention is to provide a compact arrangement for a carding machine in which more of the total surface area of the carding cylinders may be utilized for increased carding action.
Yet another object of the invention is to provide a compact carding apparatus and method which utilize reduced floor space by employing a pair of small carding cylinders and where high quality carded fiber is provided by utilizing more of the surface area of the small carding cylinders for carding.
Still another object of the invention is to provide a compact carding arrangement wherein upstanding carding cylinders provide increased carding area and accessibility to the apparatus for servicing, operation, and direct connecting to associated fiber feeding and sliver or web delivery machinery.
Still another object of the invention is to provide a carding machine having a take-off which automatically threads sliver into a coiler can of a coiler upon start-up.
Another object of the invention is to provide apparatus for automatically threading the sliver of a condensed web into a coiler can of a coiler.